3.
Why are the turbines for hydroelectric dams located far below the top of the dam?
to ensure that the water does not lose too much potential energy before reaching the turbines
to ensure that the water does not lose too much kinetic energy before reaching the turbines
to allow the kinetic energy of the water to increase greatly before reaching the turbines
to allow the potential energy of the water to increase greatly before reaching the turbines
The correct statement is: Kinetic energy is highest at the top; potential energy is highest at the bottom.
In a hydroelectric dam, as water flows from the top of the dam to the bottom, it gains potential energy due to its height above the ground. At the top of the dam, the water has the highest potential energy. As the water falls down through the dam, its potential energy is converted into kinetic energy due to its motion. Therefore, the kinetic energy is highest at the bottom of the dam, where the water is moving at its fastest velocity.
Based on the results of the investigation of mass and kinetic energy, what would you expect to happen in one drops a baseball with a mass of 145 grams? Why?
The baseball will create a larger splash because it has less mass.
The baseball will create a smaller splash because it has less mass.
The baseball will create a larger splash because it has more mass.
The baseball will create a smaller splash because it has more mass.
The correct answer is: The baseball will create a smaller splash because it has more mass.
Mass and kinetic energy are directly proportional. As the mass of an object increases, its kinetic energy also increases. When the baseball is dropped, its kinetic energy will be higher due to its greater mass compared to other objects with less mass, such as a pebble or a feather. This higher kinetic energy will allow the baseball to penetrate the materials it encounters in the water (such as the surface tension) more easily, resulting in a smaller splash. In contrast, objects with less mass would have lower kinetic energy and would create a larger splash upon impact with the water surface.
4.
A student drops a 350-gram rock and a 500-gram rock into a pool from a pool from a height of 8 meters. Which statement about the investigation is accurate?
The 500-gram rock causes a larger splash because it has more kinetic energy.
The 500-gram rock causes a smaller splash because it has more mass.
The 350-gram rock causes a smaller splash because it has more kinetic energy.
The 350-gram rock causes a larger splash because it has less mass.
The correct statement is: The 500-gram rock causes a larger splash because it has more kinetic energy.
In this scenario, both rocks are dropped from the same height, so they both have the same amount of potential energy before falling. However, the kinetic energy of an object is directly proportional to its mass. The 500-gram rock has a greater mass than the 350-gram rock, which means it will have more kinetic energy as it falls. This increased kinetic energy will allow the 500-gram rock to impact the water's surface with more force, causing a larger splash compared to the 350-gram rock.
The correct answer is: to allow the potential energy of the water to increase greatly before reaching the turbines.
By locating the turbines far below the top of the dam, water can accumulate a significant amount of potential energy as it flows down through the dam. This potential energy is then converted into kinetic energy as the water passes through the turbines, which in turn drives the generation of electricity. If the turbines were located closer to the top of the dam, there would be less potential energy and the efficiency of the hydroelectric system would be reduced.
4.
Which statement correctly identifies the relative levels of kinetic and potential energy in a hydroelectric dam?
Kinetic energy and potential energy are both highest at the bottom.
Kinetic and potential energy are both highest at the top.
Kinetic energy is highest at the bottom; potential energy is highest at the top.
Kinetic energy is highest at the top; potential energy is highest at the bottom.
1.
Two different rivers have drops that are the same height. In river A, this section of river is a waterfall. In river B, this section is a hydroelectric dam. In what way does the energy differ between the drops in the two rivers?
The potential energy of the water would be less at the top of the drop in river A than in river B.
The potential energy of the water would be greater at the top of the drop in river A than in river B.
The kinetic energy of the water would be less at the bottom of the drop in river A than in river B.
The kinetic energy of the water would be greater at the bottom of the drop in river A than in river B.
The correct answer is: The potential energy of the water would be greater at the top of the drop in river A than in river B.
In river A, where there is a waterfall, the water is falling freely under gravity with no external mechanisms or structures regulating its flow. As the water falls, it gains potential energy due to its height above the ground. In river B, with a hydroelectric dam, the movement of water is controlled and regulated by the dam structure. The water accumulates potential energy as it is stored behind the dam, but the amount of potential energy at the top of the drop would be less compared to a waterfall. In a dam, the potential energy is harnessed and converted into other useful forms, such as electrical energy through turbines.